Manufacture of superheater units.



O. K. LASSITER.

MANUFACTURE OF SUPERHEATER UNITS.

APPLICATION FILED JUNE 5, 1913 1,083,688. Patented Jan. 6, 1914.

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G. K. LASSITBR.

MANUFACTURE OF SUPERHEATER UNITS.

APPLICATION FILED JUNE 5, 191s.

1,083,688. PatentedJ an. 6, 1914;

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COLUMBUS K. LASSITER, or RICHMOND, VIRGINIA.

MANUFACTURE OF SUPERHEATER UNITS.

Specification of Letters Patent.

Patented Jan. 6, 19114.

Application filed June 5, 1913. Serial No. 771,852.

To all whom it may concern Be it known that I, COLUMBUS K. Lassrrnn, of Richmond, in the county of Henrico and State of Virginia, have invented a certain new and useful Improvement in the Manufacture of Super-heater Units, of which improvement the following is a specification.

My invention relates to superheater units of the form ordinarily applied in locomotive boiler superheaters of the fire tube type, and its object is to provide a method of construction whereby superheater units of such charact'er may be readily and inexpensively manufactured, and which will render available, as constituents thereof, drop forged or hydraulic pressed return bends, and to produce a superheater unit, as an article of manufacture, which shall be of greater strength, durability, and effectiveness in service, than those of the ordinary construction, byv reason of having its parts solidly and securely connected together, and fully exempt from liability to leakage at their junctions.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure-1 is a View in elevation, of a superheater unit manufactured under my invention; Fig. 2, a longitudinal section, on an enlarged scale,

through an end portion thereof; Fig. 3, a

view, in perspective, of a return bend body; Fig. 4, a similar view of a return bend cap; Fig. 5, a View similar to Fig. 2, showing a modified form of return bend; Fig. 6, a longitudinal section through the same, on the line a a of Fig. 5; and, Fig. 7, a transverse section, on the line b b of Fig.

As ordinarily constructed, superheater units ofthe class to which my invention re lates are composed of parallel lines of scamless steelpipes and cast steel return bends,

the ends of the lines of pipe being connected by tapping or threading them into the return bends. When so connected, leaks are frequently developed at the joints, after the units have been put in service, these being due to im/perfectly' made. or deteriorated joints, or to strains exerted on the units in removing'them from the boiler tubg; The cast steel return bends are also often found to be defective by reason of the presence of sand holes or other imperfections, necessitating their rejection and loss. These objections, which are familiar to builders and operators of locomotives fitted with super heaters, are, under my invention, cfiectively eliniinated.

Referring first to Figs. 1 to at inclusive of the drawings, for the practice of my invention, I provide a plurality of pipes, l, of

matching with, that is to say, substantially corresponding in diameter, and in thickness of metal, with the ends of the pipesto be connected, and a dished cap or cover section, 3, the form of which, at its open end is a flattened ellipse, which corresponds with that surrounding the open end of thebody section, as indicated in Figs. 3 and 4. The connection of the two lines of pipe is effectedby electrically welding the ends of the cylindrical project-ions of a body section, 2, of a return bend, to the corresponding ends of the two lines of pipe, and similarly welding a cap section, 3, to th opposite end of the body section. By reason of the correspondence, in transverse section, and consequent matching, of the ends of the therefore the welding operation may be quickly and economically effected by the ap plication of an alternating electric currentand end pressure. This would not be practicable if metal projected beyond the surfaces to be welded. The two lines of pipe .and the return bend are united by the above operation so as to form a solid, and, for practical purposes, an integral structure, which presents no joints and is thereby exempt from liability to leakage, and is not subject to the loosening strains by which the ordinary threaded connections are deteriorated and rendered unfit for eflicicntservice.

Figs. 5 to 7 inclusive illustrate a structural modification of the return bend, which,

in this case, is' provided with removable,

plugs for affording access, if desired, to the interior of the pipe lines. The body section, 2, is of similar form to that before described, and a cap section, 3 is provided, which, instead of being cupped or dished, corresponds in transverse section throughout its length, to the open end portion of the body section, and its outer end, which is plane, is provided with two openings, which are threaded, in line axially with the openings of the body sect-ion, to receive removable plugs, 5, which are cupped or hollowed interiorly, as shown, to prevent them from being burned out by theaction of the high heat to which they are subjected. Squared projections, 5, are formed on the plugs, for the application of a wrench in screwing them into and out of position. The pipe lines, 1, body section, 2, and cap section, 8, are electrically welded together, as in the instance first described. By removing the plugs, a reamer may be inserted, for the purpose of truing out the end portions of the pipes.

My invention is, so far as my knowledge and information extend, differentiated from all constructions proposed in the prior art, by the provision, as described and shown, of an independent cap, section, which is welded to the open ended body section of the return bend after the cylindrical proj ections of the body section have been welded to the two pipe lines. In the latter welding operation, when performed by the resistance electric welding process, a flash or inwardly projecting ring of metal is formed at the joints of the body section and pipe lines, the presence of which would so materially obstruct the bores of the pipes as to render them unfit for service in a superheater unit. The opposite end of the body section being, as shown, either entirely open or closed by removable plugs, the flash can be readily and quickly removed by the insertion and rotation of a reamer, before the cap is welded to the body section, and inasmuch as the inside transverse sectional area of the completed return bend is materially greater than that of the pipe lines, the reduction thereof by the flash formed at the joint of the body section and cap is inappreciable.

I clalm as my invention and desire to secure by Letters Patent:

1. As a new article of manufacture, a superheater unit comprising a return bend body having two cylindrical open ended projections disposed side by side at one of its ends, each matching the end of av line of superheater pipe and open at its opposite end, two lines of superheater pipe, each electrically welded to the end of one of said I projections, and a closure member electrically welded to the opposite end of the return bend body.

2. As a new article of manufacture, a superheater unit comprising a return" bend body having two cylindrical open ended pro-- jections disposed side by side. at one of its ends, each matching the end of a line of superheater pipe, and being entirely open at its opposite end; a return bend cap matching the opposite end of the body; and two lines of superheater pipe, the return bend body and cap being electrically welded one to the other on their matching surfaces and each of the lines of pipe being electrically welded to the matching end of one of :the projectidns of the return bend body.

3. As a new article of manufacture, a superheater unit comprising a return bend body having two cylindrical open ended projections disposed side by side at one of its ends, each matching the end of a line of superheater pipe, and being entirely open at its opposite end; a return bend cap matching the opposite end of the body; two lines of superheater pipe, the return bend body and cap being electrically welded one to the other on their matching surfaces and each of the lines of pipe being electrically welded to the matching end of one of the projections of the return Uend body, and removable plugs threaded into the outer end of the return bend cap.

a COLUMBUS K. LASSITER. 

